Slide-fastener stringer

ABSTRACT

A synthetic-resin coupling element has a plurality of annular links which are longitudinally interconnected by webs of reduced cross-sectional area so that the element can flex at these webs. Each link is square in outline with the diagonals all lying on the longitudinal axis of the fastener and each link carries a laterally and diagonally projecting coupling head. The top side of each element is formed with a longitudinally extending notch in which the stitches of the attachment tread lie. The underside of each element is provided with pointed claw-like projections which engage the fabric to which the element is to be fastened and can even serve as welding spots for bonding of the element to the textile base. Such coupling elements can be sewn directly to the fabric with conventional sewing machines.

United States Patent 1191 Hansen Nov. 20, 11973 [54] SLIDE'FASTENER STRING FOREIGN PATENTS OR APPLICATIONS Inventor! Hansen, Kopehhageh-valby, 956,320 1 1950 France 24 205.13 D Denmark 1,285,599 1 1962 France 24 205.13 D 403,541 4 1943 ital 24 205.13 D [73] Assgnw OPP'HaIdmg Glam 459,542 9i196s swiiwland 24/20513 D Switzerland [22] Filed: Sept. 27, 1971 Primary ExaminerBernard A. Gelak 21 Appl. No.; 184,056

[57] ABSTRACT [30] Foreign Apphcatmn Pnunty Data A synthetic-resin coupling element has a plurality of 10, 1970 Germany P 20 49 738-5 annular links which are longitudinally interconnected by webs of reduced cross-sectional area so that the el- LS. Cl- R, D ement can flex at these webs Eagh is quare in A44! A44b 19/04 outline with the diagonals all lying on the longitudinal Field of Search 24/205-13 20512, axis of the fastener and each link carries a laterally and diagonally projecting coupling head. The top side of each element is formed with a longitudinally ex- References Cited tending notch in which the stitches of the attachment UNITED STATES PATENTS tread lie. The underside of each element is provided 3,072,991 1 1963 Alberts 24/20513 D with Pointed claw-like Projections which engage the 3,002,244 10/1961 McNamara 24 2051 R fabric to which the element is to be fastened and can 2,525,284 10/1950 Camp 24/205.l3 D even serve as welding spots for bonding of the element 3,069,723 12/1962 Porepp 24/205.l3 D to the textile base. Such coupling elements can be 3,141,217 1964 101165 24/205l3 D sewn directly to the fabric with conventional sewing 3,330,013 7/1967 Morin 24/205.l R hi 3,414,948 12/1968 Cuckson..... 24/20513 D 3,600,766 8/1971 Alberts 24/205.l2 8 Claims, 3 Drawing Figures PATENTEUNUY 2 0 I975 SHEET 10F 3 ATTORNEY HARRY HANSEN INVENTOR.

SHEET 2 BF 3 BY Karl ATTO R NEY F IG.3

PATENTEB new 20 I975 PATENTEwnvzo ms 37 2 sum 3 BF 3 HARRY SEN INVENT BY 9. W

ATTORNEY SLIDE-FASTENER STRINGER FIELD OF THE INVENTION The present invention relates to a slide fastener. More particularly this invention concerns a syntheticresin coupling element for a slide fastener.

BACKGROUND OF THE INVENTION In recent times slide fasteners with synthetic-resin coupling elements have become well known. Typical examples are discussed in my copending applications entitled SEPARABLE SLIDE FASTENER (Ser. No. 39,629 filed 22 May 1970 now US. Pat. No. 3,618,178), SLIDE FASTENER WITH EDGE-FOLD TAPE (Ser. No. 114,330 filed Feb. 1971 now abandoned), and STRINGER FOR INVISIBLE OR CON- CEALE D SLIDE FASTENER WITH COUPLING EL- EMENT BONDED TO SUPPORT TAPE (Ser. No. 114,331 filed 10 Feb. 1971).

Slide-fasteners and coupling elements as described therein present certain clear-cut advantages over the hitherto-known metallic slide fasteners, but many have disadvantages.

Generally speaking such fasteners must be completely assembled and thereafter mounted on the garment to be provided with such a fastener. This means that an often bulky tape must be added to the garment and the tape usually must have a color matching that of the garment.

Even when provided with such a tape extreme care must be taken in the mounting of the coupling element to maintain a uniform spacing between the coupling heads or teeth of the element. Similarly a tape must be provided which has a minimum strechability so that the intertooth spacing which has been carefully set during the mounting of the element is not subsequently upset by stretching of the tape.

Those elements with sufficient longitudinal stability to avoid this problem usually have, however, the disadvantage of stiffness so that their use in supple garments is ruled out.

Finally, very complicated guide and feed devices must be provided along with the stitching or bonding equipment to insure, once again, that during attachment a precise small intertooth spacing or gauge is maintained. I

Other so-called invisible or concealed slide fasteners are known which cannot be seen when they are closed. Such fasteners must invariably be completely fabricated on their respective tapes due to the complexity of their makeup and particularly to the intricate manner in which the slider fits over them. In addition, the slider often becomes jammed since it must run directly along the support tape, quickly fraying it and eventually catching in frayed threads.

In discussing slide fasteners, it is important to distinguish between so-called continuous coupling elements of the type with which the present invention is concerned and coupling chains of discontinuous or discrete elements. In a continuous coupling element, the series of coupling heads is formed unitarily and integrally on a synthetic-resin body extending the full length of the slide fastener stringer and projecting laterally at a predetermined spacing therefrom. In slide fasteners of the discontinuous type, individual coupling heads are fixed at spaced locations to the support tape or fabric of the stringer. The term slide-fastener stringer is used herein in its customary sense to describe a slide-fastener structure consisting of a pair of support tapes carrying respective coupling elements and a slider for interleaving the coupling heads or separating them upon longitudinal movement of the slider along the stringer. End-stop members may be provided if desired.

As already noted, conventional continuous coupling elements generally have respective heads formed upon laterally projecting shanks and interfittable between the heads of the opposing coupling element. Frequently the coupling element is fastened to the support tape or fabric by a row of stitching, the stretches of which pass over the shanks of the coupling element and between the shanks to penetrate the support tape. such systems have the disadvantage, if formations are not provided to fix the shanks with respect to the attachment thread, that lateral movement of the coupling element relative to the stitching is possible. Furthermore, a definitive positioning of the stitching with respect to the coupling element is not always possible in the absence of such formations. Since the coupling elements are in the form of helices or undulating strips, longitudinal distortion is possible and the spread between coupling heads tends to vary with the manner of stitching and with stressing of the coupling element. In other words, the gauge" or interhead spacing is not well defined in these conventional structures.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide an improved slide fastener of the abovedescribed general type.

Another object is the provision of an improved synthetic-resin coupling element for a slide fastener.

Yet another object is to provide a synthetic-resin coupling element which is easy to attach to a garment or'support tape and which is dimensionally so stable in its longitudinal direction that it can be sewn directly onto a garment without the use of specialized equipment.

A further object of the present invention is the provision of an improved invisible or concealed slidefastener stringer.

SUMMARY OF THE INVENTION The above objects are attained according to the present invention by a coupling element having a plurality of annular links and a plurality of webs longitudinally interconnecting these links. Each of the links carries a laterally projecting coupling head and the webs are substantially smaller than the links to allow flexing of the .element at these webs. The entire element is unitarily formed of a thermoplastic synthetic resin by injection into fixed or movable molds. Such a fastener is longitudinally nonstretchable for two main reasons. Firstly, the closed annular form of the links resists deformation much more than the corresponding link portion on a conventional meander-or coil-type coupling element. Secondly, since the fastener is permitted to flex almost entirely at the webs, which are thinner than the links, these links can be dimensioned heavily to resist stretching.

The annular shape, which can be circular or elliptical, but is preferably polygonal, makes stitching of the element to a garment or textile support band extremely easy. The stitch length need merely be set to equal the intertooth spacing or a multiple thereof so that even a ralatively unskilled worker can quickly and easily mount such a coupling element on the edge of a piece of fabric.

Another feature of the invention resides in the formation of the coupling element as part of a so-called invisible or concealed slide fastener wherein one element according to the invention is stitched on the outside of the opening edge with its coupling heads or teeth directed away from the opening, then this edge of the support tape is folded in to hide the element.

In accordance with another feature of the invention each link is formed on its side opposite its coupling head with a flange adapted to fit into the edge of a slider. Such a flange is not fully as thick as its respective link so that the lip of the slider which reaches under it fits in a notch. The present invention also envisages a web interconnecting each of the laterally projecting flanges with its neighboring flange, such web being thinner than the flange and forming a continuous laterally projecting guide which is spared from the fabric to accommodate the slider edge. In addition such a continuous guide extending up one side ofthe coupling element resists stretching of the element to a large extent.

More specifically, the invention resides in a continuous coupling element molded from a thermoplastic synthetic resin and formed in the longitudinal direction with spaced-apart openings of constant cross-section adapted to receive the passes of a row of stitching securing the coupling element to a support tape or fabric, the regions between these openings being formed as webs of a smaller cross-section than the needle-passing eyes and enabling transverse flexure. Each of the eyes is associated with a respective coupling head interfittable with the coupling heads of a mating coupling element when both coupling elements form part of a slide fastener stringer. Each of the coupling elements thus constitutes, with the respective support tape or support fabric, a slide-fastener half. According to an important feature of the present invention, the transverse width of the web between the needle-passing eyes is a small fraction of the width of each eye and the thickness of the web in a direction perpendicular to the plane of the generally flat coupling element is likewise smaller than the otherwise substantially uniform thickness of the needle-passing eye. The webs are longitudinally channeled to accommodate the fastening stitches and preferably are provided with thread-guiding surfaces converging downwardly toward the channel to enable the thread to pass efficiently into the latter.

The upper surfaces of the needle-passing eye likewise converge downwardly and inwardly and preferably are rounded or radiused to center the needle with respect to each eye as the coupling element is affixed to the support fabric.

An important feature of the present invention resides in the provision of lateral ledges interconnecting the eyes substantially continuously along the side of the coupling elements opposite that from which the heads project. These ledges, which have a thickness less than the thickness perpendicular to the plane of the coupling element in the web region so as not to interfere with flexion of the coupling element, are underhung by inwardly turned portions of the slider and form a guide therefor. Centrally of the coupling element, i.e. along a median plane through the eyes thereof, the eyes are formed symmetrically adjoining the respective webs with pedestals and like formations adapted to support the aforementioned ledges above the fabric to accommodate the inwardly turned lips of the slider. When the eyes are formed as regular polygons with an even number of sides, as is the preferred case, the webs are provided between diagonally opposite corners of the polygons.

DESCRIPTION OF THE DRAWING The above and other objects, features, and advantages will become apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a perspective large-scale view of a fastener according to the present invention, partly in section;

FIG. 2 is a top view of one of the coupling elements shown in FIG. 1;

FIGS. 3 and 4 are side elevational views taken in the direction of arrows III and IV, respectively, of FIG. 2;

FIG. 5 is a section taken along line V V of FIG. 2, also showing the slider and support fabric;

FIG. 6 is a view similar to FIG. 2 showing an alternative embodiment of the present invention;

FIG. 7 is a section taken along line VII VII of FIG. 6; and

FIG. 8 is a view similar to FIG. 2 showing an alternative embodiment of the present invention.

SPECIFIC DESCRIPTION As seen in FIG. 1 a slide fastener has a pair of planar coupling elements I each mounted on the folded-over edge 5 of a piece of fabric 4. The elements I can be joined together by a slider 13. Each element 1 comprises a plurality of links 2 forming attachment holes 3 and interconnected by webs 7. Furthermore, each link 2 carries a coupling head 6 adapted to fit snugly between two like heads 6 of the opposite element 1. Stitching 17 passing through the holes 3 and through the flap 5 secures the elements 1 to the fabric 4.

As shown with more particularity in FIGS. 2 5, the links 2 are all square in outline and arranged such that their diagonals define a longitudinal axis A of the element 1. The sides of each link have a width w which is equal, according to the invention, to between onefourth and one-sixth of the width W of the link, here one-fifth. Each element 1 is formed with an axially extending V-shaped groove 8 having a breadth B equal to the transverse width of the opening 3 which in this case is equal to 3w. The groove or notch 8 has a depth D equal to around one-fourth B or two-thirds w. When seen from the side as in FIGS. 3 and 4, it can be seen that the sides of each link have a thickness T which is substantially greater, here by about 15 percent, than the thickness 2 of the web regions 7. Thus I is greater than T minus D as seen from the side but the thickness t of the webs at the very base of the notch 8 as seen in FIG. 5 is exactly equal to T minus D. The crosssectional area A of each web region 7 is therefore equal to 2+ t'/2 w, wherein w is the width of the web 7 orthogonal to the axis A, so that sin 1r w w, with the centerlines of the sides of the links 2 meeting at a point, as here.

On the sides ofthe links 2 toward the fabric, there are provided pointed projections 10 arranged to dig into the fabric to enhance the holding power of the element 1. Each link 2 is provided with four such claws 10 extending from regions on the underside of the link corresponding to the groove 8. A rectangular notch 18 is formed in this underside of each element 1 extending axially to enhance flexing of the element while a groove 19 orthogonal to the notch or groove 18 is formed at each web 7 to further insure that most flexing of the elements is done at these webs 7. Each projection is formed with an undersurface inclined inwardly toward the groove 18 so that its point is on its edge away from the point of the other neighboring claw. The groove 18 has a width equal to w.

Each head or tooth 6 is formed of two identical and unitary portions v6' and 6" which are geometrically congruent and axially offset from each other to form steps 16 to each side. This permits firm interlocking of two elements 1 according to principles discussed in my above-mentioned copending applications. Each head 6 has a neck 20 which has an axial dimension substantially equal to B.

On the edge of each element 1 turned away from the heads 6, there is formed a slider guide constituted by flanges 12 formed on the links 2 and webs interconnecting them. The flanges 12 have an axial dimension equal to that of the neck and a height H equal to around one'half T. The webs 15 have a height h equal to around one-third H, with the undersides of the flanges l2 and of the webs 15 forming a continuous surface for, as best shown in FIG. 5, engagement with a lip 14 formed on the edge 11 of the slider 13. For separation of the elements, a wedge-shaped body that reaches under the head region of the elements 1 is provided.

Coupling elements 1 can be provided to a garment manufacturer in spools and sewn onto the garments by the very same workers that assemble-the garments. The sewing-machine operator need merely adjust the stitch length of his machine to correspond to the spacing of the eyes 3 and then sew the fastener to the right side of the fabric to each side of the opening and with the heads directed away from the opening. Then a fold is formed as shown in FIG. 5, a slider 13 is slipped on and end-stop members are mounted. All these operations can be easily done by a conventionally skilled garment worker to produce concealed slide fasteners right in the garment, without the complication of stocking a multitude of fasteners of various colors and lengths; any length element can be cut off, and color of the element itself is of little consequence in concealed fasteners.

It should be noted that the eye 3 of each link 2 is not of regular cross section but is flared outwardly at the top or provided with an inwardly converging surface to best guide the needle of the sewing machine into it.

In FIGS. 6 and 7 a coupling element 1' is shown which corresponds to the elements 1 described above in every feature except the following: Webs 15' are provided which extend between the flanges 12 in the form of a narrow strip running along the lower outer edge of the flanges 12. The elimination of the portion of web 15 filling the entire gap between the flanges 12 serves to lighten the element, and to make it somewhat more flexible while having virtually no effect on the element's longitudinal nonstretchability. In addition each link 2 is formed with only two holding claws 10' in the form of generally V-shaped bodies which are formed with a point lying under the axis A. To this end the element 1' is not formed with the groove 18 so that the cross-sectional area of the element is reduced at the web 7 only by the notch 8, but in any case the crosssectional area at the web is smaller than the overall cross-sectional area orthogonal to the axis A taken through the link 2 at any other region.

The enlarged claws 10 are intended to be used in ultrasonic bonding or welding of the element 1' to the fabric. To this end each claw is melted into the fabric to bond integrally therewith. This can be done by simply passing a hot iron or ultrasonic probe over the wrong side of the fabric after stitching of the element thereto to melt the points of the claws 10' which will protrude somewhat. Of course, in this case the stitching may be dispensed with.

In FIG. 5, it can be seen that the surfaces S and S defining the flanks of each eye are rediused or outwardly flared to act as the guides for the needle mentioned earlier. It should also be noted that the slider is generally flat and formed with a slider channel accommodating the generally flat pair of coupling elements (FIG. 1) and that the outer ledges of the coupling elements (remote from the coupling heads) are underhung by inwardly turned lips of the slider. Thus, while the heads of the coupling elements are spaced along the stringer, the opposite side of each coupling element is generally continuous, i.e. uninterrupted.

In FIG. 8 a coupling element is shown wherein each link 2 is circular in outline and each eye 3 is similarly circular. In addition each coupling head 6' is basically round rather than diamond-shaped. Otherwise this embodiment is identical to that of FIG. 1, and would appear virtually identical in cross section.

I claim:

1. A slide-fastener stringer comprising a pair of support bands, a respective coupling element mounted on each band and matingly engageable with the coupling element of the other band, and a slider shiftable along said coupling elements for interdigitating and separating said coupling elements selectively, each coupling element comprising a plurality of generally flat annular links and a plurality of flexible webs longitudinally interconnecting said links, said webs and said links being unitarilyformed of a synthetic resin, each of said links of one of said coupling elements being formed with a laterally projecting coupling head adapted to engage between two like heads of the other coupling element, said webs being of substantially smaller thickness than said links for flexing of said element at said webs, said slider being generally flat and of a thickness approximating that of said coupling elements, said links forming openings accommodating rows of stitches affixing the respective coupling element to each band, said openings being transverse to the plane of the respective coupling element, each of said coupling elements being formed with a continuous ledge along the edge thereof opposite said heads and spaced above the respective band, said slider being generally flat and having a thickness approximately equal to that of said coupling elements and a pair of inwardly turned flanges underhanging said ledges.

2. The stringer defined in claim 1 wherein each link is polygonal in outline.

3. The stringer defined in claim 2 wherein each link is square in outline.

4. The stringer defined in claim 3 wherein each link has a diagonal extending longitudinally of said element.

5. The stringer defined in claim 1 wherein each link is provided on its side away from said head with a laterally projecting flange forming said ledge and having an upper surface continuous with a corresponding upper 7. The stringer defined in claim 1 wherein each of said links forms an inwardly converging needle-passing eye for centering a needle relative to the coupling element.

8. The stringer defined in claim 5 wherein each pedestal has a lower surface turned toward said substrate and formed with at least two longitudinally spaced claws penetrating into said band. 

1. A slide-fastener stringer comprising a pair of support bands, a respective coupling element mounted on each band and matingly engageable with the coupling element of the other band, and a slider shiftable along said coupling elements for interdigitating and separating said coupling elements selectively, each coupling element comprising a plurality of generally flat annular links and a plurality of flexible webs longitudinally interconnecting said links, said webs and said links being unitarily formed of a synthetic resin, each of said links of one of said coupling elements being formed with a laterally projecting coupling head adapted to engage between two like heads of the other coupling element, said webs being of substantially smaller thickness than said links for flexing of said element at said webs, said slider being generally flat and of a thickness approximating that of said coupling elements, said links forming openings accommodating rows of stitches affixing the respective coupling element to each band, said openings being transverse to the plane of the respective coupling element, each of said coupling elements being formed with a continuous ledge along the edge thereof opposite said heads and spaced above the respective band, said slider being generally flat and having a thickness approximately equal to that of said coupling elements and a pair of inwardly turned flanges underhanging said ledges.
 2. The stringer defined in claim 1 wherein each link is polygonal in outline.
 3. The stringer defined in claim 2 wherein each link is square in outline.
 4. The stringer defined in claim 3 wherein each link has a diagonal extending longitudinally of said element.
 5. The stringer defined in claim 1 wherein each link is provided on its side away from said head with a laterally projecting flange forming said ledge and having an upper surface continuous with a corresponding upper surface of said link and a lower surface lying in a plane above a corresponding lower surface of said link, said lower surface forming part of a pedestal supporting said ledge in spaced relationship above the band.
 6. The stringer defined in claim 5, further comprising further a web formed between each of said flanges and the neighboring flange, said further webs having lower surfaces continuous with the lower surfaces of said flanges and constituting therewith a continuous slider guide.
 7. The stringer defined in claim 1 wherein each of said links forms an inwardly converging needle-passing eye for centering a needle relative to the coupling element.
 8. The stringer defined in claim 5 wherein each pedestal has a lower surface turned toward said substrate and formed with at least two longitudinally spaced claws penetrating into said band. 